Fluid-proportioning apparatus



I. LUNDGAARD.

FLUID PROPORTIONING APPARATUS.

APPLICATION FILED $EPT.8, l9l7- 1,333,986. Patented Mar. 16, 1920.

IN VENTOR W 9% [VarZ zurqgaazfl (A TTOR/VEVS IVAB LUNDGAABD, OF ROCHESTER, NEW YORK.

FLUID-PROPOBTIONING APPARATUS.

Specification of Letters Patent.

Patented Mar. 16, 1920.

Application filed September 8, 1917. Serial No. 180,327.

constant and predetermined relative Volumes or amounts through the provision of automatic means whereby compensation is made for expected or posslble difi'erences 1n the characteristics of the two fluids" with respect to aggregate form, specific gravity, pressure, temperature or otherwise. The invention is intended to provide a practicable, simple apparatus of this nature, susceptible of different uses, and the operation of which will be eflicient, accurate, and dependable To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

The drawing is a more or less diagrammatic view, partially in section and partially in elevation, of a form of apparatus illustrating a practical embodiment of my improvement.

The invention may be carried out in a number of ways, and is susceptible of a variety of applications as for instance in carbureters for explosive engines, or air and gas mixers for gas furnaces, or in other relations that make it desirable to bring together two or more fluids in constant proportion. irrespective of variations in the amounts. The primary object of my invention is accomplished in the present instance through the instrumentality of pressure controlled diaphragms, which are arranged in pressure chambers, and suitably oonnected with a governing valve member in one of the fluid conductors. so that the volume in the valve controlled conductor will be increased or decreased in accordance with variations in the other fluid conductor. I accomplish this by taking advantage of th relation of the fluid velocities, and corresponding velocity heads in different tubes of predetermined cross sectional areas, and by utilizing the different pressures resulting from different velocities. Thus, I obtain a pressure differential which acts upon a diaphragm in one of the pressure chambers, and is counterbalanced by a corresponding pressure differential in the second conductor. Any change of volume in one conductor causes a change of its pressure differential and consequently a movement of its diaphragm, and the governing valve to which it is connected, until the flow in the second conductor is so modified that its pressure differential will balance that of the first conductor and thus reestablish a normal proportion.

In the structure shown in the drawing, 1 and 2 indicate the fluid conductors, and in order to have a concrete example, it will be supposed that gas is flowing in the conductor 1 and air in the conductor 2, and that it is desired to control the supply of air in accordance with the volume of gas. To this end, I employ a governing valve member 3 in the conductor 2. The valve member 3 is carried by a pivotally mounted arbor 4, at

the outer end of which 'is fixed an arm 5 connected by means of a link 6 to the rod 7. The parts last mentioned constitute means connecting the valve member with the pressure differential controlled instrumentalities in the pressure chambers. The pressure chambers are designated generally by 1 and 2, being separated by a central wall 8, but these may be otherwise constructed or arranged. The chambers contain diaphragms, indicated at 1 and 2", respectively secured at their peripheries to the inner wall of the chamber, and dividing the chambers into high pressure sides 1 and 2 and low pressure sides 1 and 2 The diaphragms 1 and 2 are both fixedly mounted upon the aforesaid rod 7 and are movable in their respective chambers, in accordance with variations of the relative fluid volumes.

- The pressure differential, or velocity head differential, may be obtained in different ways, the details of which form no part of my invention, and I have illustrated one method of accomplishing this, which I will now describe. The conductor 1 is provided with a restricted portion or throat 1, and openings 1, leading to a passage 1, which communicates with the low pressure side of chamber 1 by means of the pipe 1, and 1' is a pipe connecting the high pressure side of the chamber 1 with the conductor 1 at the enlarged portion or zone a). The fluid conductor 2 has a corresponding throat 2, openings 2 and passage 2 connected by pipe 2 with the low pressure side of chamber 2, and 2 is a pipe connecting the high pressure side of chamber 2 with the conductor 2 at the enlarged portion or zone 3 The difference in the areas or cross sectional contours of the fluid conductors at the enlarged zones .r. 1 and the smaller zones 1 and 2, causes a the pressure differential in the one conductor, under normal conditions, is the same as the pressure differential in the other conductor, and these are so associated with the pressure chambers as to oppose each other, and thus maintain the governing valve and its connecting devices in a state of equilibrium.

Upon a variation in the volume or velocity of gas passing through the conductor 1, there will occur a corresponding change in the pressure differential for the same conductor, that is to say, the difference between the pressures at the enlarged and restricted zones will change. This will cause a movement of the diaphragmsin the pressure chambers owing to the fact that the pressure differential in conductor 1 will, for the time being, exceed or be less than the pressure differential in conductor 2.' This causes a movement of the governing valve 3 and effects a change in the volume of air flowing through conductor 2 until the pressure di ferential in the latter again reaches a point of equality with the pressure differential in conductor 1, and the diaphragms l and 2 are again brought to a state of equilibrium by an equality of the opposing pressures.

It will be understood that my invention may be carried out by obtaining velocity head differentials in different ways, a further instance of which is found in the Pitot tube consisting of two tubes liaving upstream and down-stream inlets extending in opposite directions in the conductor when the flow takes place. My improvement resides generally in maintaining a constant proportion of flow of the same or different fluids in two fluid conductors dependent on the predetermined cross sectional areas of the conductors and effecting this through a valve in one, governed by the resultant force from the respective fluid differentials of the two conductors acting in opposition and which finally counterbalance each other.

I claim as my invention:

1. In a fluid proportioning apparatus, the combination with two conductors each provided with a Venturi tube' and means for regulating the rate of flow through one of the conductors, of an actuator for the regulator operated by the resultant force of the differential pressure in one conductor opposed to the differential pressure in the other..

2. In a fluid proportioning apparatus, the combination with two conductors each provided with means for creating a differential pressure therein and means for regulating the rate of flow through one of the conductors, of an actuator for the regulator operated by the resultant force of the differential pressure in one conductor opposed to the differential pressure in the other.

IVAR LUND GAARD. 

